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Bacillus anthracis

About: Bacillus anthracis is a research topic. Over the lifetime, 3994 publications have been published within this topic receiving 128122 citations.


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Journal ArticleDOI
TL;DR: This article reviews the accumulated evidence for immunization, either active or passive, to counter the malicious release of anthrax spores and suggests that combining antibiotic prophylaxis and active immunization before illness onset may offer the best combination of prompt and sustained protection.
Abstract: Anthrax spores rank as the leading threat among bioweapons. This article reviews the accumulated evidence for immunization, either active or passive, to counter the malicious release of anthrax spores. The key protective factor in current anthrax vaccines for humans is a protein called protective antigen, which allows ingress of toxins into cells. The US vaccine is licensed to prevent anthrax, regardless of the route of exposure. Its dosing schedule is cumbersome and somewhat painful (shortcomings that may be resolved by ongoing clinical studies). It can be prescribed with the confidence commensurate with dozens of human safety studies and experience in 1.8 million recent vaccinees. For post-exposure prophylaxis, combining antibiotic prophylaxis and active immunization before illness onset may offer the best combination of prompt and sustained protection, especially for people who inhale large doses of spores. To treat anthrax infection, passive immunization using a polyclonal or monoclonal antibody product may offer important clinical benefit, especially if the anthrax bacteria are resistant to multiple antibiotics.

77 citations

Journal ArticleDOI
TL;DR: A simple membrane strip-based biosensor for the detection of viable B. anthracis spores was developed and combined with a spore germination procedure as well as a nucleic acid amplification reaction to identify as little as one viable B- anthracis spore in less than 12 h.
Abstract: A simple membrane strip-based biosensor for the detection of viable B. anthracis spores was developed and combined with a spore germination procedure as well as a nucleic acid amplification reaction to identify as little as one viable B. anthracis spore in less than 12 h. The biosensor is based on identification of a unique mRNA sequence from the anthrax toxin activator (atxA) gene encoded on the toxin plasmid, pXO1. Preliminary work relied on plasmid vectors in both E. coli and B. thuringiensis expressing the atxA gene. Once the principle was firmly established, the vaccine strain of B. anthracis was used. After inducing germination and outgrowth of spores of B. anthracis (Sterne strain), RNA was extracted from lysed cells, amplified using nucleic acid sequence-based amplification (NASBA), and rapidly identified by the biosensor. While the biosensor assay requires only 15-min assay time, the overall process takes12 h for the detection of as little as one viable B. anthracis spore, and is shortened significantly, if larger amounts of spores are present. The biosensor is based on an oligonucleotide sandwich-hybridization assay format. It uses a membrane flow-through system with an immobilized oligonucleotide probe that hybridizes with the target sequence. Signal amplification is provided when the target sequence hybridizes to a second oligonucleotide probe that has been coupled to dye-encapsulating liposomes. The dye in the liposomes then provides a signal that can be read visually or quantified with a hand-held reflectometer. The biosensor can detect as little as 1.5 fmol of target mRNA. Specificity analysis revealed no crossreactivity with closely related species such as B. cereus, B. megaterium, B. subtilis, B. thuringiensis etc.

77 citations

Journal ArticleDOI
TL;DR: It is concluded that calcium is required at several steps in the intoxication of cells by anthrax lethal toxin, including involvement of calmodulin at a step during intoxication.
Abstract: Anthrax lethal toxin, which consists of two separate proteins, protective antigen (Mr, 82,700) and lethal factor (Mr, approximately 83,000), is cytotoxic to the macrophagelike cell line J774A.1. Removal of calcium from the culture medium protected cells against the action of lethal toxin. Calcium depletion during the binding phase of intoxication afforded only partial protection. Further analysis showed that calcium removal caused some inhibition of protective antigen binding but that it had minimal effect on proteolytic conversion of protective antigen to the active 63-kilodalton fragment and that it had no effect on lethal factor binding. Cells to which lethal toxin had bound in the presence of calcium were protected when transferred to calcium-depleted culture medium, indicating a role for calcium at a postbinding stage. When ammonium chloride is present with lethal toxin, toxin accumulates in intracellular vesicles. Calcium-free medium protected these cells upon removal of the amine block, suggesting that calcium is also required at a step after internalization of lethal toxin. Calcium channel blockers inhibited 45Ca2+ uptake and protected cells against cytotoxicity. Calmodulin inhibitors also protected against the action of lethal toxin, suggesting involvement of calmodulin at a step during intoxication. We conclude that calcium is required at several steps in the intoxication of cells by anthrax lethal toxin.

77 citations

01 Jan 1996
TL;DR: In conducting research using animals, the investigators adhered to the “Guide for the Care and Use of Laboratory Animals,” prepared by the Committee on Care and use of Laboratory animals of the Institute of Laboratory Animal Resources, National Research Council (NIH Publication No. 8623, revised 1985).
Abstract: In conducting research using animals, the investigators adhered to the “Guide for the Care and Use of Laboratory Animals,” prepared by the Committee on Care and Use of Laboratory Animals of the Institute of Laboratory Animal Resources, National Research Council (NIH Publication No. 8623, revised 1985). The views, opinions and/or findings contained in this publication are those of the authors and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation.

77 citations

Journal ArticleDOI
TL;DR: The use of high pressure for spore inactivation represents a considerable improvement over other available methods of spores inactivation and could be of interest for antigenic spore preparation.
Abstract: Spores of Bacillus anthracis are known to be extremely resistant to heat treatment, irradiation, desiccation, and disinfectants. To determine inactivation kinetics of spores by high pressure, B. anthracis spores of a Sterne strain-derived mutant deficient in the production of the toxin components (strain RP42) were exposed to pressures ranging from 280 to 500 MPa for 10 min to 6 h, combined with temperatures ranging from 20 to 75°C. The combination of heat and pressure resulted in complete destruction of B. anthracis spores, with a D value (exposure time for 90% inactivation of the spore population) of approximately 4 min after pressurization at 500 MPa and 75°C, compared to 160 min at 500 MPa and 20°C and 348 min at atmospheric pressure (0.1 MPa) and 75°C. The use of high pressure for spore inactivation represents a considerable improvement over other available methods of spore inactivation and could be of interest for antigenic spore preparation.

76 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
202381
2022169
202181
2020116
2019106